Valve-geab



UNITED STATES PATENT OFFICE.

J. P. ROSS, OF LEWISBURG, PENNSYLVANIA.

VALVE-GEAR OF DIRECT-ACTION STEAM-ENGINES.

Specification of Letters Patent No. 16,809, dated March 10, 1857.

To aZZ whom t may concern.'

Be it lmown that I, JAMES P. Ross, of Lewisburg, in the county of Unionand State of Pennsylvania, have invented a new and useful Improvement inthe Valve-Gear of Direct-Action Steam-Engines; and I do hereby declaret-hat the following is a full, clear, and exact description of the same,reference being had to the accompanying drawings, making a part of thisspecication, in which- Figure l is a side view, partly in section of ablowing engine, with my improved valve gear. Fig. 2 is a plan of thesame. Fig. 3 is a transverse vertical section of the same, in the linem, of Fig. l. Fig. l is a Side view of the principal parts of the valvegear, detached from the engine.

Similar letters of reference indicate corresponding parts in each of theseveral figures.

This invention consists in the combination, with an oscillating yoke ofsimilar character to that described in the specification of LettersPatent granted to me on the 22nd day of January, 1856, of an elasticlever, by whose action on the yoke, a movement is suddenly given tostart or give a lead to the valve or valves, just at the termination ofthe stroke of the piston in either direction, to admit steam to thecylinder for the return stroke of the piston. This elastic leverperformed this duty in a more efficient manner than the two counterpoiselevers and the weights described in my former patent above referred to,and makes the construction of the valve gear more simple.

To enable others to make and use my invention, I will proceed todescribe its construction and operation.

A, is the framing of the engine, supporting at one end the blowingcylinder B, and at the other the steam cylinder C, which are arranged inline with each other.

D, is the piston of the steam cylinder, connected by the piston rod Ewith the piston of the blowing cylinder.

F, is the steam chest of the cylinder C, containing a valve a, of thekind generally known as the short slide valve.

T, is the steam pipe.

S, is the exhaust pipe.

Z), b1, are the two steam passages leading from the valve seat toopposite ends of the steam cylinder; and c, is the exhaust passage.

CZ, is the valve stem, working in a guide e, attached to the cylinder.

G, is a standard, erected upon one side of the framing A, about midwaybetween the two cylinders, for the support of the oscillating yoke, H,and the elastic lever I, oper-` ating in connection with it. Theoscillating yoke H is attached, at the center of its length, to a shorthorizontal axle f, which is fitted to oscillate in a bearing at the topof the standard G; said axle occupying a position transverse to thepiston rod; and the elastic lever I is fitted, at the center of itslength, to oscillate upon a stud g, which is secured in the standard G,directly under the axle f. The yoke H, has a short arm 2f, standingperpendicularly or nearly so to the main portion of it, which isconsiderably longer than the intended length of stroke of the piston;said short arm carrying a stud h, to which the valve stem eZ, isconnected by a rod w. The main portion of the said yoke has, on the sidenext the piston rod, a rim z', which extends the whole length thereof,close to its upper edge; and below this rim there are two cams j, j', ofsimilar elliptic form, projecting from the same side of the yoke, one oneach side of its center of oscillation (viz., the axle f) and belowthese cams, under the center f, there is a projecting piece 7c, theupper side of which has two inclinations, which form continuations ofthe curves of the upper sides of the cams y', j- The elastic lever I,which is of about the same length as the main portion of the oscillatingyoke, is curved somewhat like the rim z', on the yoke. It may be made ofiron or steel; but iron will afford suflicient elasticity, as the leveris of considerable length in proportion to the amount of iexure to whichit is submitted to develop its elasticity. It has, jointed to one end, arod Z, which passes through a hole in the corresponding end of the yoke;and the end of this rod Z, has a screw-thread cut on it to receive a nuta, above the yoke; and at the opposite end of the elastic lever, thereis a piston rod E, and working in a guide 0, 0, attached to the framing,as the piston rod moves back and forth. This cross-head has secured toit a plate p, one side of which is extended (as shown at Q91) to formwhat may be termed a traveler, which passes between the rim z', the camsj, j, and the projecting piece 7c, of the yoke; the said traveler, asthe piston works back and forth, describing the line indicated in Fig.4, by the dots. The same head-piece has also attached to it a stud s,which is fitted with a roller r, which travelsV under the elastic leverI.

The yoke receives the oscillating movement by which it operates thevalve, through the action of the traveler 79, upon the yoke itself, andthe action of the roller o", upon the elastic lever I, in the followingmanner :-In the several strokes of the piston, the traveler 2)', passesfirst under one of the cams j, j, and then over the other, as indicatedby the arrows in Fig. 4. In passing under either cam, it raises one endof the yoke, according to the direction of the piston, and depresses theother end; and by that means it causes the arm t, to move the valve; butas the valve must have made half its stroke, and a little beyond forlead, before the piston commenced the stroke, the movement thus given bythe action of the traveler only completes the stroke, and gives a fullopening to the port. The first portion of the stroke of the valve,#viz.,a portion suflicient to close the one steam passage and give the valve alead to open the port of the opposite passage,-is effected by the actionof the roller 1*, on the under side of the elastic lever I, during thetime the traveler is passing over the cams; the said roller forcing upthat end of the elastic lever against which it comes in contact, anddepressing the other end; thus causing the rod Z, or Z, and the nut n,or n, at the latter end, to pull down the end of the yoke with which itis connected, as far as is permitted by the upper side of the cam overwhich the traveler is passing, which cam is pressed up against thetraveler by the lever I; the form of the said side of the camcontrolling the movement of the yoke produced by the lever, andregulating the movement of the valve in closing the port. The roller r,by its action on the curved under side of the elastic lever I, asaforesaid,- while an uncontrolled movement of the yoke, under theinfluence of the said lever, is prevented by the cam bearing against thetraveler,-strains and bends the lever I, and causes it to assume thecharacter of a spring; and as soon as the traveler passes the outerextremity of the cam, the yoke, being left free to the influence of thelever, derives, from the elastic action which the latter exercises inresuming its condition of rest, a very sudden movement, that issufficient to carry the valve far enough to give sufficient opening tothe port of the passage which has previously been exhausting, to admitsteam to commence the return stroke of the piston. To illustrate thisoperation, the valve, the yoke, the elastic lever, and theirconnections, and the traveler, are all shown in two positions in Fig. 4.In the position shown in bold outline, which corresponds with theposition shown in Fig. 1, the piston is near the end of its stroke; theroller 11, is forcing up the left hand end of the elastic lever, whoseopposite end is consequently pulling down the corresponding end of theyoke, and moving the valve to shut off the steam from the right handport 5'; the movement of the yoke, and consequently that of the valve,being controlled by the action of the traveler upon the upper side ofthe cam y'. The closing of the port is completed at or before thearrival of the traveler at the outer extremity of the cam j; and as thetraveler passes the said extremity of the cam, the yoke, no longerhaving its movement controlled by the cam, suddenly has its right handend thrown up, and its left hand end thrown down, by the elastic actionof the lever, far enough to carry the valve over the outer edge of theport Y); by which steam is admitted to the left hand side of the pistonC, which then commences its stroke to the right. The traveler now movesunder the cam jl, completing the opening of the valve as it does so, asillustrated by the red diagram in Fig. 4. The action of the traveler onthe cam j, and the action of the roller on the right hand end of theelastic lever, is precisely the same as that above described andillustrated in Fig. 4, only that the movements are in oppositedirections. The length of the stroke of the piston is determined by thedistance between the most distant extremities of the two cams and thelength of the traveler from point to point; the sum of the abovedistance and length giving the exact length of stroke.

The amount of lead given to the valve, by the action of the elasticlever on the yoke, can be increased or diminished by screwing the nutsa, al, lower down or yhigher up the rods Z, Z1.

The invention, when applied to pumping engines, or to engines fordriving reciprocating saws by a direct connection with the piston, or toany other direct-action engines, is applied in the same manner as to theblowing engine above described. It will work equally well on ahorizontal, upright,

or inclined engine, and with a long slide valve, two short valves, orwith a rolling valve or valves; but no particular description of itsapplication to other valves than that show-n is necessary, as thedescription already given is suflicient to enable the skilled engineerto adapt it to any other The elastic lever I, applied `and operatingvalve to Which it may be applicable. substantially as described, incombination Instead of arranging the elastic lever to With theoscillating yoke H, the traveler p1,

Work on a fixed center g, below the Working and the roller r, or itsequivalent, for the 5 center of the oscillating yoke, it may bearpurposes set forth.

ranged to Work upon the same center as the J P ROSS yoke, or on a pin orstud attached to the r yoke, below the Working center thereof.Vitnesses:

That I claim as my invention, and desire HUNTER PARDOE, 10 to secure byLetters Patent, is: JOHN KALER.

